Flores R, Daròs J A, Hernández C
Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Spain.
Adv Virus Res. 2000;55:271-323. doi: 10.1016/s0065-3527(00)55006-4.
This chapter focuses on the second viroid family, whose members are also referred to as hammerhead viroids, taking into account their most outstanding feature. If the word “small” is the first to come to mind when considering viroids, perhaps the second word is “hammerhead,” because this class of ribozymes, which because of its structural simplicity has an enormous biotechnological potential, is described in avocado sunblotch viroid (ASBVd) as well as in a viroid-like satellite RNA. The most outstanding feature of the members is their potential to adopt hammerhead structures in both polarity strands and to self-cleave accordingly. Viroids differ from viruses not only in their genome size but also in other fundamental aspects, prominent among which is the lack of messenger activity of both viroid RNAs and their complementary strands.
本章聚焦于第二个类病毒家族，考虑到其最显著的特征，该家族成员也被称为锤头状类病毒。在想到类病毒时，如果首先想到的是“小”这个词，那么第二个词可能就是“锤头状”，因为这类核酶由于其结构简单而具有巨大的生物技术潜力，在鳄梨日斑类病毒（ASBVd）以及一种类病毒样卫星RNA中都有描述。该家族成员最突出的特征是它们在两条极性链中都有形成锤头状结构并相应地进行自我切割的潜力。类病毒与病毒的不同之处不仅在于它们的基因组大小，还在于其他一些基本方面，其中最突出的是类病毒RNA及其互补链都缺乏信使活性。
